Thalamus and Internal Capsule Flashcards
What sense does not go through the thalamus?
Smell
What are the 3 groups of the cerebral cortex?
Cerebellum
Brainstem
Basal Ganglia
What is the general function of the cerebellum?
It makes sure that the movements are correct and adjusts them if they are not.
What is the general function of the basal ganglia?
Coordinates motor activity between agonist and antagonist muscle groups.
Information from where is generally sent to the thalamus?
Cerebellum and Basal Ganglia as well as sensory inputs from STT
What is the general function of the thalamus?
It decides what information is important and passes it on, acting as a filtering center, however, it does not make these decisions on its own.
What does the 3rd ventricle lie between?
It lies between the left and right thalami.
What divides up the thalamus?
Internal Medullary Well/Lamina
What forms a thin sheet surrounding the thalamus?
Thalamic Reticular Nuclei
What parts is the thalamus divided into?
– Anterior division nuclei
– Medial division nuclei
– Lateral division nuclei
What junction lies between the thalami?
Junction of the Interventricular Foramen
What are the 3 functional groups of the thalamus?
Specific/Relay Nuclei
Association Nuclei
Non-Specific Nuclei
What are the characteristics of specific/relay nuclei?
They have specific functions such as vision or hearing and well defined outputs and projections.
What area of the body is the VPM nucleus generally associated with?
Head and face
What area of the body is the VPL nucleus generally associated with?
Body besides the head and the face
What are the characteristics of the association nuclei?
They are reciprocally attached to the association cortex and they receive more processing information than sensory information
What are the inputs of the specific/relay nuclei?
Regulatory inputs from the cerebral cortex, reticular formation and reticular nucleus.
Specific inputs from the basal ganglia, spinal cord, retina, etc.
What are the inputs of the association nuclei?
ONLY receives regulatory inputs from the cerebral cortex, reticular formation and reticular nucleus.
What are the general characteristics of the non-specific nuclei?
Different point to point connections than the specific nuclei
What is the function of the reticular nucleus?
Projects to other thalamic nuclei rather than the cerebral cortex and control the flow of information.
How is information from the thalamus carried?
Through the thalamic peduncles
What information goes to the ventral anterior and ventral lateral nucleus and where is it projected?
Basal Ganglia and Cerebellum and it is projected to Motor Areas (pre central gyrus)
What information goes to the ventral posteriolateral nucleus and where is it projected?
Medial Lemniscus and the STT (spinal components) and it is projected to the Somatosensory Cortex (postcentral gyrus)
What information goes to the ventral posteriomedial nucleus and where is it projected?
Medial Lemniscus and the STT (trigeminal components) and it is projected to the Somatosensory Cortex (postcentral gyrus)
What information goes to the medial geniculate nucleus and where is it projected?
Brachium of the inferior colliculus and it is projected to the Auditory Cortex in the temporal lobe
What information goes to the lateral geniculate nucleus and where is it projected?
Optic Tract and it is projected to the Visual Cortex in the occipital lobe
What information goes to the anterior nucleus and where is it projected?
Mammilothalamic Tract and it is projected to the Cingulate Nucleus
What would be the result of a stroke on the left side of the PCA?
It would affect the right side of the body
What neurons does the thalamus consist of?
It consists of projection and inhibitory neurons (GABA neurons)
What neurotransmitters do most of the specific inputs to the thalamus use?
Glutamate
What are the 4 thalamic peduncles?
Anterior
Posterior
Inferior
Superior
What is the path of the anterior peduncle?
It passes through the anterior limb of the internal capsule to reach the prefrontal and cingulate gyrus
What is the path of the posterior peduncle?
It passes through the retrolenticular part of the internal capsule to reach the occipital lobes, posterior parietal and temporal
What is the path of the inferior peduncle?
It passes through the sublenticular part of the capsule, below the lentiform nucleus to reach the anterior temporal and orbital cortex
What is the path of the superior peduncle?
It passes through the posterior limb of the internal capsule to reach the premotor, motor and somatic sensory cortex
